Simulation of smaller systems

A better way to simulate less amount of memory is to reduce the amount of memory available to the partition.

When used on POWER4-based MCM systems, the rmss command allocates memory from the system without respect to the location of that memory to the MCM. Detailed specific performance characteristics may change depending on what memory is available and what memory is assigned to a partition. For example, if you were to use the rmss command to simulate an 8-way partition using local memory, the actual assigned memory is not likely to be the physical memory closest to the MCM. In fact, the 8 processors are not likely to be the 8 processors on an MCM, but will instead be assigned from the available list.

When deconfiguring CPUs on an MCM-based system, there are subtleties involved when the hypervisor implicitly using pathways between MCMs and memory. While the performance impacts are small, there can be some slight differences that may affect detailed performance analysis.